Ken Thompson: The Death of a Visionary Prosecutor

In 2013 Mr. Thompson was elected as Brooklyn’s first black district attorney, beating out an entrenched incumbent, Charles Hynes, whose decades-long tenure had devolved into a stew of misconduct and corruption.

Mr. Thompson vowed to clean up the office — a promise he was making good on until his unexpected death on Sunday, at 50, from cancer.

The tragedy is, of course, greatest for his family. But Mr. Thompson’s death is also a big blow to the broader cause of progressive prosecutorial reform nationwide, and to the recognition by law enforcement leaders of pervasive racial disparities across the criminal justice system.

His earliest and perhaps bravest move was to call into question his predecessor’s long record of winning convictions based on dubious evidence or prosecutorial wrongdoing. To date, Mr. Thompson’s conviction-review unit has identified and reversed the convictions of 21 people, all black or Latino, who collectively spent hundreds of years in prison. He also stopped prosecuting people for low-level marijuana offenses and spearheaded a program aimed at helping more than a quarter-million Brooklyn residents erase outstanding warrants for minor offenses. Versions of both programs have now been adopted citywide.

Mr. Thompson had said he was inspired to enter law enforcement by his mother, who worked as one of New York City’s first female police officers on patrol while raising her children in a Harlem public-housing project. After law school, he served as a federal prosecutor before starting a private practice focusing on civil-rights and discrimination cases. His intimacy with the perspectives of both law enforcement and minority communities made him unusually well positioned to balance a respect for the justice system even as he fought to fix it from the inside. But his efforts to strike that balance also exposed him to intense criticism from all sides, as when he recommended no jail time for a police officer he had successfully prosecuted for the fatal shooting of an unarmed black man in 2014.

When Mr. Thompson ran for office, this page expressed reservations over his lack of significant managerial experience and his publicity-seeking behavior as a private lawyer, factors that made him “not an ideal successor” to Mr. Hynes. But we recommended voting for him in the belief that he would follow through on his reformist platform.

We were happy to have been proved wrong about his ability to run the third-biggest prosecutor’s office in the country, and right about his commitment to a boldly progressive agenda that has become a national model. That agenda is now being overseen by Eric Gonzalez, who as Mr. Thompson’s second in command worked closely with him on his top initiatives, and who was sworn in as acting district attorney on Tuesday. Gov. Andrew Cuomo, who has the authority to name Mr. Thompson’s replacement, would honor his legacy best by leaving Mr. Gonzalez in place until next year’s election.

Speaking to The Times in May, Mr. Thompson said: “Protesters want revolution in the criminal justice system overnight. That won’t happen. The way we’ll bring permanent reforms is when people like me get off sidelines and decide to spend a life of public service.”